Self-filling water bottle mimics Namib beetle's water-trapping wings

A US startup is developing a self-filling water bottle that
sucks moisture from the atmosphere to create condensation, in the
same way the humble Namib desert beetle does.

The beetle, endemic to Africa's Namib desert -- where there is
just 1.3cm of rainfall a year -- has inspired a fair few
proof-of-concepts in the academic community, but this is the first
time a self-filling water bottle has been proposed. The beetle
survives by collecting condensation from the ocean breeze on the
hardened shell of its wings. The shell is covered in tiny bumps
that are water attracting (hydrophilic) at their tips and
water-repelling (hydrophobic) at their sides. The beetle extends
and aims the wings at incoming sea breezes to catch humid air; tiny
droplets 15 to 20 microns in diameter eventually accumulate on its
back and run straight down towards its mouth.

NBD Nano, made up of two
biologists, an organic chemist and a mechanical engineer, is
building on past studies that constructed structurally superior
synthetic copies of the shell. An earlier incarnation of the
material was first
constructed in 2006 by an MIT team -- they dipped glass or
plastic substrates into solutions of charged polymer chains over
and over again to manipulate the surface make-up. Silica
nanoparticles were then added to create a rougher, water-trapping
texture, and a Teflon-like substance sealed it. Charged polymers
and nanoparticles were then layered in patterns to create a
contrast between rough and porous surfaces.

NBD Nano says it has achieved proof of concept with its dual
water-attracting (superhydrophilic) and water-repelling
(superhydrophobic) bottle design, and is currently working on a
prototype and seeking funding. Incredibly, the team predicts that
the bottle could collect between half a litre and three litres of
water per hour, depending on the local environment.

"Dry places like the Atacama Desert or Gobi Desert don't have
access to a lot of sources of water," cofounder Miguel Galvez told the
BBC. "So if we're creating [several] litres per day in a
cost-effective manner, you can get this to a community of people in
Sub-Saharan Africa and other dry regions of the world. And if you
can do it cheaply enough, then you can really create an impact on
the local environment."

However it's not likely it will immediately be used in arid
environments such as the Namib, but instead on green roofs and
greenhouses. It may also be used by the military, before eventually
becoming a portable, self-filling water bottle for rain-poor
nations. The latter is "a conceptual design that one day could be
feasible, although it could be years away" state NBD Nano. However,
it is unlikely it could fulfill all a community's needs, from home
use and cooking to farming, but would perhaps instead act as an
emergency device.

The Namib beetle had already inspired the 2011 International
Dyson Award-winner, Edward Linacre, who designed the Airdrop -- an irrigation system that pumps then cools air
through underground pipes to create condensation at plant
roots.

Comments

Incorrect usage of English: "Self-filling water bottle mimics Namib beetle's water-trapping wings"... use of 'mimics' i.e. present simple, suggests this is a FACT, but this is not the currently case, as the project is by no means complete. The article states that there is not yet even a prototype.

Try 'will mimic' instead for more accuracy.

You're welcome.

Dr. Thropplenoggin

Nov 26th 2012

In reply to Dr. Thropplenoggin

Throp, are you trying to sound smart? Nobody (myself included) reading this article is incapable of applying such basic english to a piece of writing. Besides, who cares? The author told me what I wanted to know, in an interesting and well-done article. Get over yourself.

Landen

Nov 26th 2012

Could there be a long term effect of a lower humidity? Could that be a problem?